Try putting some "time" in. When we were slower and wanted more work in the neighborhood. We would work slower at the account or chat with the costumer(up sell). Arrive at different times and days. Brake up the extras into smaller jobs. Use the nearest gas station. Drive around the area before and/or after servicing the account. Be creative. I find this method works well. It also goes hand in hand with good service. Often the good costumers are loyal to their lawn turd. But, The will come you way in due "time"